In vehicles, shock absorber regulators are currently typical. In such regulators, the goal is pursued of stabilizing either the bodywork or the unsprung masses. A regulator typically includes sensors, electronics, and actuators. The switching speed receives particular significance. The more rapidly a movement state may be sensed, analyzed, and readjusted by the actuator, the better. However, parameters such as power consumption and forces are to be considered. Ultimately, the regulation is always only a response to an undesired state. The problem is that such regulators use complex hardware and software and very rapid regulators result in a high power consumption and high wear. However, at the same time the stabilizing of the unsprung masses requires a high speed in particular, because their characteristic frequency is approximately one order of magnitude higher than the characteristic frequency of the structure.
Known regulators have distance, pressure, and/or acceleration sensors, one or more CPUs, and actuator valves, which are valves or electrical force elements, depending on the system. If an undesired movement state is recognized by one or more sensors, the shock absorber may be varied in a range between hard and soft, so that as a result an improving or at least not worsening force may act on the bodywork and/or the axle.
FIG. 11 shows an illustration of a typical air bellows, which may be used as a shock absorber if the bellows piston forms a separate volume, which is connected to the bellows volume by a throttle or a valve having throttling action. The air bellows has a base 302, a bellows piston 304, a bellows rubber 306, and a bellows cover 308.
Air shock absorbers may have an interposed throttle, which may regulate the gas stream.
Up to this point, throttle elements which have a fixed throttle cross section or throttles which have a cross section which changes as a function of the pressure differential in the bellows and in the auxiliary volume have been known.
Prof. Gold showed already in the 1970's that there is a maximum damping work for such damping systems, which may not be increased further using a typical arrangement.
For most applications in vehicles, the damping work resulting therefrom is too low, so that the use as a shock absorber is not possible. A system thus becomes possible for primary shock absorbers of vehicles if the damping work is more than doubled by targeted influence on the throttle during an oscillation amplitude, i.e., at least 10 Hz.
FIG. 12 shows the way in which the throttle must be adjusted between open and closed for the targeted influence. Time t is plotted on the abscissa and amplitude A is plotted on the ordinate. Time intervals 1201 identify states in which the throttle is closed and time intervals 1202 identify states in which the throttle is open.
It is ideal, but technically impossible, for a complete air exchange to occur in an infinitely short time in particular dead centers (TDC, BDC).
In such a system, the damping work is the area in an F-s graph (force-distance graph).
FIG. 13 shows a comparison of a regulated throttle to an unregulated throttle in such an F-s graph. An area 1301, which corresponds to “regulated shock absorber work” and an area 1302, which corresponds to “unregulated shock absorber work,” are shown.
The requirement for such a valve and such a regulator is the high regulating speed and the large valve cross sections for the large air mass compensation.
An adjustment by a pressure or distance sensor, which recognizes the dead centers or an approach to the dead centers, in connection with regulation electronics and a special valve, is fundamentally possible.
The high valve and electronics costs and the complex regulator are disadvantageous in such an approach.